1. Statement of the Technical Field
The inventive arrangements relate to interconnect feed devices for transmitting radio frequency (RF) energy between two or more electrical components, such as but not limited to an antenna element unit and associated transmit/receive electronics of a phased-array antenna system.
2. Description of Related Art
Many types of electronic devices require the transmission of RF energy between two or more components thereof. For example, in phased-array antenna systems, RF signals are transmitted between an array antenna having a plurality of antenna element units that radiate and receive RF energy, and transmit/receive electronics that transmit and receive the outgoing and incoming RF signals. Transmission and reception of the RF signals is accomplished via an interconnecting feed commonly comprising coaxial cables.
In some types of phased-array antenna systems, each antenna element unit may include as many as four constituent radiating feed arms that each require an RF signal path to an associated set of transmit/receive electronics. These signal paths need to be of substantially the same length, to maintain the RF signals in phase as they travel between the transmit/receive electronics and the antenna element unit. Also, the interface location points for the feed on the transmit/receive electronics are often arranged in a linear pattern, while the interface locations on the antenna element unit are arranged in a diagonal or square pattern. Thus, maintaining signal paths of substantially equal length in the feed often requires complex and precise cable routing to transition between the interface locations. The expense and time needed to construct a feed using such routing can be substantial. In fact, the combined cost of the feeds in a typical phased-array antenna system can represent between 20 to 30 percent of the overall cost of the antenna element array.